/**
* Copyright 2010 The Apache Software Foundation
*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.hadoop.hbase.ipc;
import java.io.IOException;
import java.util.List;
import org.apache.hadoop.hbase.ClusterStatus;
import org.apache.hadoop.hbase.HColumnDescriptor;
import org.apache.hadoop.hbase.HTableDescriptor;
import org.apache.hadoop.hbase.UnknownRegionException;
import org.apache.hadoop.hbase.client.coprocessor.Exec;
import org.apache.hadoop.hbase.client.coprocessor.ExecResult;
import org.apache.hadoop.hbase.security.TokenInfo;
import org.apache.hadoop.hbase.security.KerberosInfo;
import org.apache.hadoop.hbase.snapshot.HSnapshotDescription;
import org.apache.hadoop.hbase.util.Pair;
/**
* Clients interact with the HMasterInterface to gain access to meta-level
* HBase functionality, like finding an HRegionServer and creating/destroying
* tables.
*
* <p>NOTE: if you change the interface, you must change the RPC version
* number in HBaseRPCProtocolVersion
*
*/
@KerberosInfo(
serverPrincipal = "hbase.master.kerberos.principal")
@TokenInfo("HBASE_AUTH_TOKEN")
public interface HMasterInterface extends VersionedProtocol {
/**
* This Interfaces' version. Version changes when the Interface changes.
*/
// All HBase Interfaces used derive from HBaseRPCProtocolVersion. It
// maintained a single global version number on all HBase Interfaces. This
// meant all HBase RPC was broke though only one of the three RPC Interfaces
// had changed. This has since been undone.
// 29: 4/3/2010 - changed ClusterStatus serialization
// 30: 3/20/2012 - HBASE-5589: Added offline method
// NOTE: Not bumped from 29 to maintain compatibility since this addition is
// after the v0.92.0 releases this is applied to. This is not bumped for
// 0.94.0 to maintain rolling restart compatibility with 0.92.x.
public static final long VERSION = 29L;
/** @return true if master is available */
public boolean isMasterRunning();
// Admin tools would use these cmds
/**
* Creates a new table asynchronously. If splitKeys are specified, then the
* table will be created with an initial set of multiple regions.
* If splitKeys is null, the table will be created with a single region.
* @param desc table descriptor
* @param splitKeys
* @throws IOException
*/
public void createTable(HTableDescriptor desc, byte [][] splitKeys)
throws IOException;
/**
* Deletes a table
* @param tableName table to delete
* @throws IOException e
*/
public void deleteTable(final byte [] tableName) throws IOException;
/**
* Used by the client to get the number of regions that have received the
* updated schema
*
* @param tableName
* @return Pair indicating the number of regions updated Pair.getFirst() is the
* regions that are yet to be updated Pair.getSecond() is the total number
* of regions of the table
* @throws IOException
*/
public Pair<Integer, Integer> getAlterStatus(byte[] tableName)
throws IOException;
/**
* Adds a column to the specified table
* @param tableName table to modify
* @param column column descriptor
* @throws IOException e
*/
public void addColumn(final byte [] tableName, HColumnDescriptor column)
throws IOException;
/**
* Modifies an existing column on the specified table
* @param tableName table name
* @param descriptor new column descriptor
* @throws IOException e
*/
public void modifyColumn(final byte [] tableName, HColumnDescriptor descriptor)
throws IOException;
/**
* Deletes a column from the specified table. Table must be disabled.
* @param tableName table to alter
* @param columnName column family to remove
* @throws IOException e
*/
public void deleteColumn(final byte [] tableName, final byte [] columnName)
throws IOException;
/**
* Puts the table on-line (only needed if table has been previously taken offline)
* @param tableName table to enable
* @throws IOException e
*/
public void enableTable(final byte [] tableName) throws IOException;
/**
* Take table offline
*
* @param tableName table to take offline
* @throws IOException e
*/
public void disableTable(final byte [] tableName) throws IOException;
/**
* Modify a table's metadata
*
* @param tableName table to modify
* @param htd new descriptor for table
* @throws IOException e
*/
public void modifyTable(byte[] tableName, HTableDescriptor htd)
throws IOException;
/**
* Shutdown an HBase cluster.
* @throws IOException e
*/
public void shutdown() throws IOException;
/**
* Stop HBase Master only.
* Does not shutdown the cluster.
* @throws IOException e
*/
public void stopMaster() throws IOException;
/**
* Return cluster status.
* @return status object
*/
public ClusterStatus getClusterStatus();
/**
* Move the region <code>r</code> to <code>dest</code>.
* @param encodedRegionName The encoded region name; i.e. the hash that makes
* up the region name suffix: e.g. if regionname is
* <code>TestTable,0094429456,1289497600452.527db22f95c8a9e0116f0cc13c680396.</code>,
* then the encoded region name is: <code>527db22f95c8a9e0116f0cc13c680396</code>.
* @param destServerName The servername of the destination regionserver. If
* passed the empty byte array we'll assign to a random server. A server name
* is made of host, port and startcode. Here is an example:
* <code> host187.example.com,60020,1289493121758</code>.
* @throws UnknownRegionException Thrown if we can't find a region named
* <code>encodedRegionName</code>
*/
public void move(final byte [] encodedRegionName, final byte [] destServerName)
throws UnknownRegionException;
/**
* Assign a region to a server chosen at random.
* @param regionName Region to assign. Will use existing RegionPlan if one
* found.
* @param force If true, will force the assignment.
* @throws IOException
* @deprecated The <code>force</code> is unused.Use {@link #assign(byte[])}
*/
public void assign(final byte [] regionName, final boolean force)
throws IOException;
/**
* Assign a region to a server chosen at random.
*
* @param regionName
* Region to assign. Will use existing RegionPlan if one found.
* @throws IOException
*/
public void assign(final byte[] regionName) throws IOException;
/**
* Unassign a region from current hosting regionserver. Region will then be
* assigned to a regionserver chosen at random. Region could be reassigned
* back to the same server. Use {@link #move(byte[], byte[])} if you want
* to control the region movement.
* @param regionName Region to unassign. Will clear any existing RegionPlan
* if one found.
* @param force If true, force unassign (Will remove region from
* regions-in-transition too if present as well as from assigned regions --
* radical!.If results in double assignment use hbck -fix to resolve.
* @throws IOException
*/
public void unassign(final byte [] regionName, final boolean force)
throws IOException;
/**
* Offline a region from the assignment manager's in-memory state. The
* region should be in a closed state and there will be no attempt to
* automatically reassign the region as in unassign. This is a special
* method, and should only be used by experts or hbck.
* @param regionName Region to offline. Will clear any existing RegionPlan
* if one found.
* @throws IOException
*/
public void offline(final byte[] regionName) throws IOException;
/**
* Run the balancer. Will run the balancer and if regions to move, it will
* go ahead and do the reassignments. Can NOT run for various reasons. Check
* logs.
* @return True if balancer ran and was able to tell the region servers to
* unassign all the regions to balance (the re-assignment itself is async),
* false otherwise.
*/
public boolean balance();
/**
* Turn the load balancer on or off.
* @param b If true, enable balancer. If false, disable balancer.
* @return Previous balancer value
*/
public boolean balanceSwitch(final boolean b);
/**
* Turn the load balancer on or off.
* It waits until current balance() call, if outstanding, to return.
* @param b If true, enable balancer. If false, disable balancer.
* @return Previous balancer value
*/
public boolean synchronousBalanceSwitch(final boolean b);
/**
* Get array of all HTDs.
* @return array of HTableDescriptor
*/
public HTableDescriptor[] getHTableDescriptors();
/**
* Get array of HTDs for requested tables.
* @param tableNames
* @return array of HTableDescriptor
*/
public HTableDescriptor[] getHTableDescriptors(List<String> tableNames);
/**
* Executes a single {@link org.apache.hadoop.hbase.ipc.CoprocessorProtocol}
* method using the registered protocol handlers.
* {@link CoprocessorProtocol} implementations must be registered via the
* {@link org.apache.hadoop.hbase.master.MasterServices#registerProtocol(Class, CoprocessorProtocol)}
* method before they are available.
*
* @param call an {@code Exec} instance identifying the protocol, method name,
* and parameters for the method invocation
* @return an {@code ExecResult} instance containing the region name of the
* invocation and the return value
* @throws IOException if no registered protocol handler is found or an error
* occurs during the invocation
* @see org.apache.hadoop.hbase.master.MasterServices#registerProtocol(Class, CoprocessorProtocol)
*/
public ExecResult execCoprocessor(Exec call)
throws IOException;
public long snapshot(final HSnapshotDescription snapshot)
throws IOException;
public List<HSnapshotDescription> getCompletedSnapshots()
throws IOException;
public void deleteSnapshot(final HSnapshotDescription snapshot)
throws IOException;
public boolean isSnapshotDone(final HSnapshotDescription snapshot)
throws IOException;
public void restoreSnapshot(final HSnapshotDescription request)
throws IOException;
public boolean isRestoreSnapshotDone(final HSnapshotDescription request)
throws IOException;
}